Current interrupt device based on thermal activation of frangible glass bulb

ABSTRACT

Embodiments described herein relate generally to a current interrupt device (CID) including a frangible bulb that is configured to be thermally triggered. In some embodiments, the CID includes a breaking contact electrically coupled to a fixed contact and held in electrical contact by the frangible bulb. In some embodiments, the frangible bulb is configured to break at a temperature threshold. In some embodiments, the breaking contact is configured to bend, rotate and/or otherwise deform about a hinge point in order to become electrically disconnected from the fixed contact when the frangible bulb breaks. In some embodiments, opening the electrical circuit between the breaking contact and the fixed contact may prevent overcharging, overvoltage conditions, overcurrent conditions, thermal runaway, and/or other catastrophic failure events.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 62/689,460 entitled, “Current InterruptDevice Based on Thermal Activation of Frangible Glass Bulb,” filed Jun.25, 2018, the disclosure of which is incorporated herein by reference inits entirety.

BACKGROUND

Many electrochemical cells (e.g., lithium ion batteries) are susceptibleto damage when subjected to abuse conditions (e.g., overcharge,over-temperature, overvoltage, unwanted or uncontrolled short circuits).Redundant monitoring systems are often required, adding significantcomplexity and cost to large-scale energy storage systems and limitingtheir adoption. Current interrupt devices (CIDs) are often used as asafety feature for electrochemical cells to prevent overcharging and/orshort-circuiting, which can lead to catastrophic failure of theelectrochemical cell. Existing CIDs often use the internal pressuregenerated within the electrochemical cell as a means to interrupt ordisconnect the active cell elements from the electrical current path.This method of current interruption can lead to gas exposure and mayresult in catastrophic failure for the electrochemical cell.

SUMMARY

Embodiments described herein relate generally to a current interruptdevice (CID) including a frangible bulb that is configured to bethermally triggered. In some embodiments, the CID includes a breakingcontact electrically coupled to a fixed contact and held in electricalcontact by the frangible bulb. In some embodiments, the frangible bulbis configured to break at a temperature threshold. In some embodiments,the breaking contact is configured to bend, rotate and/or otherwisedeform about a hinge point in order to become electrically disconnectedfrom the fixed contact when the frangible bulb breaks. In someembodiments, opening the electrical circuit between the breaking contactand the fixed contact may prevent overcharging, overvoltage conditions,overcurrent conditions, thermal runaway, and/or other catastrophicfailure events. In some embodiments, the CID can be positionedsufficiently close to an electrochemical cell such that a temperature ofthe frangible bulb is substantially similar to an operating temperatureof the electrochemical cell and such that the frangible bulb breaks whenthe temperature within the electrochemical cell is substantially similarto the temperature threshold. In some embodiments, the heat is providedby one of the cell terminals, e.g., the cathode tab or the anode tab. Insome embodiments, the heat is provided by the cell tabbing. In someembodiments, the CID can include a resistor configured to heat thefrangible bulb to above the temperature threshold when the currentthrough the breaking contact reaches a current threshold. In someembodiments, the CID can include a diode and a heating element, thediode configured to keep the heating element disconnected from currentbelow a voltage threshold. In some embodiments, once the voltage reachesor exceeds the voltage threshold, the diode can connect the heatingelement to the circuit above the voltage threshold, the heating elementbeing configured to heat the frangible bulb to above the temperaturethreshold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a current interrupt device, according to someembodiments.

FIG. 2 illustrates an interior view of a current interrupt device,according to an embodiment.

FIG. 3A illustrates a current interrupt device in a first configuration,according to an embodiment.

FIG. 3B illustrates the current interrupt device of FIG. 3A in a secondconfiguration.

FIG. 4 illustrates an electrochemical cell including a current interruptdevice, according to an embodiment.

FIG. 5 illustrates a side view of a current interrupt device, accordingto an embodiment.

FIG. 6 illustrates a top portion of an electrochemical cell including acurrent interrupt device, according to an embodiment.

FIG. 7 illustrates a current interrupt device, according to anembodiment.

FIG. 8 illustrates an interior view of a current interrupt device,according to an embodiment.

FIG. 9 illustrates an electrochemical cell including a current interruptdevice, according to an embodiment.

FIG. 10 illustrates an interior view of a current interrupt device,according to an embodiment.

DETAILED DESCRIPTION

Embodiments described herein relate generally to current interruptdevices (CIDs) configured to be thermally triggered in response to atleast one of overcurrent conditions, overvoltage conditions, and thermalrunaway. As described herein, the CIDs include a breaking contactelectrically coupled to a fixed contact and held in electrical contactthereto by a frangible bulb. In some embodiments, the frangible bulbdefines a cavity configured to contain a liquid and a gas. In someembodiments, the liquid and/or the gas contained in the frangible bulbcan be selected to expand volumetrically, causing the frangible bulb tobreak at a temperature threshold. In some embodiments, since thefrangible bulb is positioned to hold the breaking contact and the fixedcontact in electrical communication, when the frangible bulb breaks thebreaking contact can become electrically disconnected from the fixedcontact. In some embodiments, at least a portion of the breaking contactcan bend, rotate, and/or otherwise deform about a hinge point once thefrangible bulb breaks. In some embodiments, opening the electricalcircuit between the breaking contact and the fixed contact may preventovercharging, overvoltage conditions, overcurrent conditions, thermalrunaway, and/or other catastrophic failure events.

In electrochemical cell design (e.g., for Li-ion batteries), safety isone of the primary areas of concern. In certain conditions where thecell is overcharged or short circuited, there is a potential for suddenrelease of stored energy resulting in catastrophic failure (i.e.,explosion, fire, flying parts, etc.). Other ways in whichelectrochemical cells can fail include but are not limited to externalshort circuit, internal short circuit, dendrite formation, separatorfailure, impact/puncture short circuit, overcharge, over-discharge,external overheating, self-overheating, cell rupture, fire/explosion dueto flammable/explosive gas generation, etc. To prevent catastrophicfailure during these conditions it is desirable to interrupt the flow ofenergy into and out of the cell. This can be accomplished in severalways, including physically disconnecting or breaking the electricalcurrent path into the cell. Typical CIDs used in electrochemical cellsare very costly and complex to implement, with suspect reliability.

As used in this specification, the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, the term “a member” is intended to mean a singlemember or a combination of members, “a material” is intended to mean oneor more materials, or a combination thereof.

The term “substantially” when used in connection with “cylindrical,”“linear,” and/or other geometric relationships is intended to conveythat the structure so defined is nominally cylindrical, linear or thelike. As one example, a portion of a support member that is described asbeing “substantially linear” is intended to convey that, althoughlinearity of the portion is desirable, some non-linearity can occur in a“substantially linear” portion. Such non-linearity can result frommanufacturing tolerances, or other practical considerations (such as,for example, the pressure or force applied to the support member). Thus,a geometric construction modified by the term “substantially” includessuch geometric properties within a tolerance of plus or minus 5% of thestated geometric construction. For example, a “substantially linear”portion is a portion that defines an axis or center line that is withinplus or minus 5% of being linear.

As used herein, the term “set” and “plurality” can refer to multiplefeatures or a singular feature with multiple parts. For example, whenreferring to a set of electrodes, the set of electrodes can beconsidered as one electrode with multiple portions, or the set ofelectrodes can be considered as multiple, distinct electrodes.Additionally, for example, when referring to a plurality ofelectrochemical cells, the plurality of electrochemical cells can beconsidered as multiple, distinct electrochemical cells or as oneelectrochemical cell with multiple portions. Thus, a set of portions ora plurality of portions may include multiple portions that are eithercontinuous or discontinuous from each other. A plurality of particles ora plurality of materials can also be fabricated from multiple items thatare produced separately and are later joined together (e.g., via mixing,an adhesive, or any suitable method).

As used herein, the term “about” and “approximately” generally mean plusor minus 10% of the value stated, e.g., about 250 μm would include 225μm to 275 μm, about 1,000 μm would include 900 μm to 1,100 μm.

In some embodiments, a CID can be operably coupled to an electrochemicalcell and can include a breaking contact electrically coupled to a fixedcontact, a frangible bulb configured to keep the breaking contactcoupled to the fixed contact and configured to break at a temperaturethreshold, and a shutter configured to be interposed between thebreaking contact and the fixed contact when the frangible bulb breaks.In some embodiments, the frangible bulb defines a cavity containing atleast one of a quantity of a gas and a quantity of a liquid.

In some embodiments, the CID can include a diode configured to not allowcurrent to reach a heating element when the cell voltage is below avoltage threshold and to allow current to reach the heating element ator above the voltage threshold. In other words, the diode can beforward-biased such that the diode is activated only when the cellvoltage reaches or exceeds a cut-in voltage in a forward direction. Insome embodiments, the heating element can be positioned sufficientlyclose to the frangible bulb such that when the diode provides current tothe heating element, the frangible bulb can heat up and break once thetemperature of the liquid inside the frangible bulb reaches thetemperature threshold. In some embodiments, the temperature thresholdcan be greater than about 80° C., greater than about 90° C., greaterthan about 100° C., greater than about 150° C., or between about 80° C.and about 200° C., inclusive of all values and ranges therebetween.

In some embodiments, the shutter can be spring-loaded such that when thefrangible bulb breaks, stored potential energy in the spring applies aforce to the shutter, causing the shutter to be interposed between thebreaking contact and the fixed contact. In some embodiments, the shuttercan include or be made from an electrically insulating material. In someembodiments, interposing the shutter between the breaking contact andthe fixed contact can disconnect the electrical contact between thebreaking contact and the fixed contact. In some embodiments,electrically disconnecting the breaking contact from the fixed contactcan stop electrical current into or out of the electrochemical cell towhich the CID is operably coupled.

In some embodiments, the CID can further include a resistor configuredto heat the frangible bulb when a current through the breaking contactis greater than or equal to a current threshold. In some embodiments,the fixed or breaking contacts may be configured to heat the frangiblebulb via Ohmic heating when a current through the fixed or breakingcontact is greater or equal to a current threshold.

In some embodiments, the CID can be positioned sufficiently close to theelectrochemical cell such that a temperature of the quantity of theliquid within the frangible bulb is substantially similar to theoperating temperature of the electrochemical cell.

In some embodiments, the CIDs described herein can be used to protect anelectrochemical cell from at least one of an overvoltage condition, anovercurrent condition, and an over-temperature condition. In someembodiments, the method of use of the CID can include electricallycoupling the CID to at least one of an anode tab and a cathode tab. Insome embodiments, the method can further include allowing the thermallyresponsive frangible bulb to break when the liquid expands to fill theclosed interior region in response to a change in temperature in excessof the temperature threshold range. In some embodiments, the method caninclude resetting the CID after an initial thermal activation of the CIDby breaking the frangible bulb. In some embodiments, the method caninclude resetting the shutter into position such that it is notinterposed between the breaking contact and the fixed contact, e.g., byloading the spring. In some embodiments, the method can includeresetting the breaking contact into electrical contact with the fixedcontact. In some embodiments, the method can include positioning anunbroken second frangible bulb into place such that the frangible bulbmaintains the electrical contact between the breaking contact and thefixed contact while the electrochemical cell is operating normally.

FIGS. 1, 2, 3A, and 3B illustrate a current interrupt device 100 (CID100) configured to disconnect electrical current across a cathode tab(not shown) or an anode tab (not shown) to prevent overcharging,short-circuit, overcurrent conditions, overvoltage conditions, and/orthermal runaway of an electrochemical cell (not shown). In someembodiments, the CID 100 can be connected to the cathode tab or theanode tab such that, during normal operation of the electrochemicalcell, the CID 100 does not impede the charging or discharging of theelectrochemical cell. In some embodiments, the CID 100 can include abreaking contact 102 and a fixed contact 104. In some embodiments, thebreaking contact 102 and the fixed contact 104 can include the samematerials chosen to be compatible with the electrochemistry of theelectrode to which the CID 100 is electrically coupled. In someembodiments, the breaking contact 102 and/or the fixed contact 104 caninclude but are not limited to copper, aluminum, titanium, any of thesematerials coated in one of nickel, tin, silver, or gold, other suitablematerials, and combinations thereof.

In some embodiments, a frangible bulb 106 can be positioned in such away as to keep the breaking contact 102 electrically coupled to thefixed contact 104 during normal operation of the CID 100. In someembodiments, the frangible bulb 106 can provide enough contact forcebetween the fixed contact 102 and the breaking contact 104 to maintain alow-resistance contact therebetween. In some embodiments, the frangiblebulb 106 can be held in place using a set screw 108. In someembodiments, a leaf spring, plug, wedge, or other mechanism can be usedto hold the frangible bulb 106 in place. In some embodiments, anexpanding foam, polymer, resin, or other material can be used to holdthe frangible bulb 106 in place within the CID 100. In some embodiments,contacting surfaces can be positioned around the frangible bulb 106 suchthat the frangible bulb 106 is held substantially in place during use ofthe CID 100. In some embodiments, the frangible bulb can 106 can definea cavity (not shown) configured to contain a liquid and/or a gas. Insome embodiments, the liquid and/or the gas can expand and contractvolumetrically as the temperature changes. In some embodiments, theliquid and/or the gas can expand volumetrically when the temperaturerises above a temperature threshold, breaking the frangible bulb 106.

In some embodiments, the frangible bulb 106 can be substantiallycolumnar, spherical, cylinder, cone, cube, cuboid, hexagonal prism,square-based pyramid, tetrahedron, triangular prism, octagonal prism,ellipsoid, octahedron, dodecahedron, icosahedron, octahedron, polygonalstructures, or combinations thereof. In some embodiments, the frangiblebulb 106 can have a largest dimension that relates to the length of thefrangible bulb 106 and relates substantially to the distance between theset screw 108 and the breaking contact 102 or a contact surfacethereupon. In some embodiments, the frangible bulb 106 can have alargest dimension greater than about 0.5 mm, about 1 mm, about 2 mm,about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm,about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm,about 20 mm, about 21 mm, about 22 mm, about 23 mm, about 24 mm, about25 mm, about 26 mm, about 27 mm, about 28 mm, about 29 mm, about 30 mm,about 31 mm, about 32 mm, about 33 mm, about 34 mm, about 35 mm, about36 mm, about 37 mm, about 38 mm, about 39 mm, about 40 mm, about 50 mm,about 60 mm, about 70 mm, about 80 mm, about 90 mm, about 100 mm, orgreater than about 150 mm, inclusive of all values and rangestherebetween. In some embodiments, the frangible bulb 106 can have alargest dimension less than about 150 mm, about 100 mm, about 90 mm,about 80 mm, about 70 mm, about 60 mm, about 50 mm, about 40 mm, about39 mm, about 38 mm, about 37 mm, about 36 mm, about 35 mm, about 34 mm,about 33 mm, about 32 mm, about 31 mm, about 30 mm, about 29 mm, about28 mm, about 27 mm, about 26 mm, about 25 mm, about 24 mm, about 23 mm,about 22 mm, about 21 mm, about 20 mm, about 19 mm, about 18 mm, about17 mm, about 16 mm, about 15 mm, about 14 mm, about 13 mm, about 12 mm,about 11 mm, about 10 mm, about 9 mm, about 8 mm, about 7 mm, about 6mm, about 5 mm, about 4 mm, about 3 mm, about 2 mm, less than about 1mm, or less than about 0.5 mm, inclusive of all values and rangestherebetween. In some embodiments, the frangible bulb 106 can have alargest dimension between about 1 mm and about 150 mm, about 2 mm andabout 100 mm, about 3 mm and about 90 mm, about 4 mm and about 80 mm,about 5 mm and about 70 mm, about 6 mm and about 60 mm, about 7 mm andabout 50 mm, about 8 mm and about 40 mm, about 9 mm and about 30 mm,about 10 mm and about 25 mm, about 11 mm and about 24 mm, about 12 mmand about 23 mm, about 13 mm and about 22 mm, about 14 mm and about 21mm, about 15 mm and about 20 mm, about 0.5 mm and about 50 mm, about 0.5mm and about 45 mm, about 0.5 mm and about 40 mm, about 0.5 mm and about35 mm, about 0.5 mm and about 30 mm, about 0.5 mm and about 25 mm, about0.5 mm and about 20 mm, about 0.5 mm and about 15 mm, about 0.5 mm andabout 10 mm, about 0.5 mm and about 5 mm, or about 0.5 mm and about 2.5mm, inclusive of all values and ranges therebetween.

In some embodiments, the frangible bulb 106 can include a glass shelldefining an inner cavity, the glass shell having particular strength,thermophysical, shape, and dimensional characteristics such that theglass shell breaks when the liquid expands to exert a precise hydraulicpressure on the glass shell.

In some embodiments, the frangible bulb 106 can be initially filled orpartially filled with a liquid, the remaining space being largely abubble. In some embodiments, the liquid can have a low freezing point, alarge co-efficient of (thermal) expansion, slight compressibility, a lowspecific heat, and/or a reluctance to retain air in solution. In someembodiments, when the frangible bulb 106 is exposed to risingtemperature, the liquid can expand and gradually the bubble can decreasein size, the air being forced into solution because of the increasingpressure and in spite of the elevated temperature. In some embodiments,once all of the gas becomes dissolved in the liquid and the liquidexpands to fill the frangible bulb 106, the frangible bulb 106 can beconfigured to break in response to the hydraulic pressure of theexpanding liquid. In some embodiments, the glass shell can be engineeredto break locally at a particular hydraulic pressure associated with aprecise temperature: the temperature threshold. Without wishing to bebound by any particular theory, since the gas is dissolved within theliquid, when the frangible bulb 106 ruptures, a rapid depressurizationoccurs, rapid effervescence of the gas from the liquid may cause morecatastrophic failure of the frangible bulb 106 and complete release ofthe pressure holding the breaking contact 102 in electrical connectionwith the fixed contact 104.

In some embodiments, the liquid can be any suitable fluid as describedabove, including but not limited to glycerine, ethylene glycol,polyethylene glycol, aniline, bromoform, di-iodine methane, mercury,carbon tectrachloride, alcohol, tetrachloroethane, acetone, amylacetate, triethylene glycol, glycol diacetate, ethylene glycol,glycerol, other dielectric fluids commonly used for heat transferapplications, trichloromethane, tetrachloroethylene, perchloroethylene,the chemical groups consisting of derivatives of aromatic hydrocarbonscontaining two or more halogen substituents, aliphatic amides, 1,2Dibromobenzene, 1,3 Dichlorobenzene, 1,3 Dioxolane, 1 Bromo 3Chlorobenzene, benzene for which two or more hydrogens are substitutedby a halogen, 1,3 dibromobenzene, Cyclohexane, Formamide, N,NDimethylformamide, Propanone (Acetone), Tetrachloroethylene, orcombinations thereof.

In some embodiments, the temperature threshold at which the frangiblebulb 106 fractures is between about 60° C. and about 200° C., betweenabout 65° C. and about 195° C., between about 70° C. and about 190° C.,between about 75° C. and about 185° C., between about 80° C. and about180° C., between about 85° C. and about 175° C., between about 90° C.and about 170° C., between about 95° C. and about 165° C., between about100° C. and about 160° C., between about 105° C. and about 155° C.,between about 110° C. and about 150° C., between about 115° C. and about145° C., between about 120° C. and about 140° C., between about 60° C.and about 195° C., between about 60° C. and about 190° C., between about60° C. and about 185° C., between about 60° C. and about 180° C.,between about 60° C. and about 175° C., between about 60° C. and about170° C., between about 60° C. and about 165° C., between about 60° C.and about 160° C., between about 60° C. and about 155° C., between about60° C. and about 150° C., between about 60° C. and about 145° C.,between about 60° C. and about 140° C., between about 60° C. and about135° C., between about 60° C. and about 130° C., between about 60° C.and about 125° C., between about 60° C. and about 120° C., between about60° C. and about 115° C., between about 60° C. and about 110° C.,between about 60° C. and about 105° C., between about 60° C. and about100° C., between about 60° C. and about 95° C., between about 60° C. andabout 90° C., between about 60° C. and about 85° C., between about 60°C. and about 80° C., between about 65° C. and about 200° C., betweenabout 70° C. and about 200° C., between about 75° C. and about 200° C.,between about 80° C. and about 200° C., between about 85° C. and about200° C., between about 90° C. and about 200° C., between about 95° C.and about 200° C., between about 100° C. and about 200° C., betweenabout 105° C. and about 200° C., between about 110° C. and about 200°C., between about 115° C. and about 200° C., between about 120° C. andabout 200° C., between about 125° C. and about 200° C., between about130° C. and about 200° C., between about 135° C. and about 200° C.,between about 140° C. and about 200° C., between about 145° C. and about200° C., between about 150° C. and about 200° C., between about 155° C.and about 200° C., between about 160° C. and about 200° C., betweenabout 165° C. and about 200° C., between about 170° C. and about 200°C., between about 175° C. and about 200° C., or between about 180° C.and about 200° C., inclusive of all values and ranges therebetween. Insome embodiments, the temperature threshold at which the frangible bulb106 fractures is greater than about 60° C., about 65° C., about 70° C.,about 75° C., about 80° C., about 85° C., about 90° C., about 95° C.,about 100° C., about 105° C., about 110° C., about 115° C., about 120°C., about 125° C., about 130° C., about 135° C., about 140° C., about145° C., about 150° C., about 155° C., about 160° C., about 165° C.,about 170° C., about 175° C., about 180° C., about 185° C., about 190°C., about 195° C., or greater than about 200° C., inclusive of allvalues and ranges therebetween. In some embodiments, the temperaturethreshold at which the frangible bulb 106 fractures is less than about200° C., about 195° C., about 190° C., about 185° C., about 180° C.,about 175° C., about 170° C., about 165° C., about 160° C., about 155°C., about 150° C., about 145° C., about 140° C., about 135° C., about130° C., about 125° C., about 120° C., about 115° C., about 110° C.,about 105° C., about 100° C., about 95° C., about 90° C., about 85° C.,about 80° C., about 75° C., about 70° C., about 65° C., about 60° C., orless than about 50° C., inclusive of all values and ranges therebetween.

In some embodiments, the glass shell of the frangible bulb 106 can bescored or otherwise weakened at a particular location such that fractureinitiation can begin at the particular location and escaping liquidand/or gas can be directed away from the breaking contact 102 and fixedcontact 104. In some embodiments, escaping liquid and/or gas can bedirected towards an absorptive material such that the liquid does notleak into the electrochemical cell.

In some embodiments, the CID 100 can include more than one frangiblebulb 106, for example two, three, four, five, six, seven, eight, nine,or ten frangible bulbs 106. In some embodiments, when the CID 100includes more than one frangible bulb 106, the risk of accidental(unwanted) triggering of the CID 100 and disconnection of the breakingcontact 102 from the fixed contact 104 may be lower. In someembodiments, especially when the electrochemical cell is used in moredamage-prone applications, the frangible bulb 106 may fracture, e.g.,due to sudden movement of the CID 100 or due to impact from movingobjects. For instance, in automotive applications where theelectrochemical cell is part of a battery pack that may be prone tojostling and vibrations during normal use, including more than onefrangible bulb 106 in the CID 100 can reduce the risk of unintendedtriggering of the CID 100 during normal operation of the electrochemicalcell.

In some embodiments, the CID 100 can include a contact pad 110positioned between the frangible bulb 106 and the breaking contact 102.In some embodiments, the contact pad 110 can be affixed to the breakingcontact 102. In some embodiments, the contact pad 110 can be configuredto have a contact surface that holds one end of the frangible bulb 106in place against the contact pad 110. In some embodiments, the contactpad 110 can have a concave portion configured such that a convex portionof the frangible bulb 106 can come to rest in the concave potion of thecontact pad 110 when the frangible bulb 106 is positioned within the CID100. In some embodiments, the contact pad 110 can include an insulatingmaterial such as a plastic such that the frangible bulb 106 is insulatedfrom the electrical current being communicated through the breakingcontact 102 and into the fixed contact 104.

In some embodiments, when the frangible bulb 106 breaks, a shutter 112can be allowed to separate the breaking contact 102 from the fixedcontact 104 by being physically interposed therebetween. In someembodiments, the shutter 112 can include an electrically insulatingmaterial such that when the shutter 112 is interposed between thebreaking contact 102 and the fixed contact 104, the breaking contact 102can become electrically disconnected from the fixed contact 104. In someembodiments, the shutter can include any suitably insulating material,including but not limited to wood, ceramics, plastics, glass, porcelain,clays, minerals, and combinations thereof. In some embodiments, theshutter 112 can be configured to have a thicker portion tapering to apointed distal portion. In some embodiments, the breaking contact 102can extend beyond the end of the fixed contact 104. In some embodiments,the shutter 112 can be configured to apply perpendicular force to theportion of the breaking contact 102 that extends beyond the fixedcontact 104 in order to electrically disconnect the breaking contact 102from the fixed contact 104. In some embodiments, the breaking contact102 can include a contact surface such that the shutter 112 can applyforce against the contact surface to electrically disconnect thebreaking contact 102 from the fixed contact 104. In some embodiments,the CID 100 can further include a spring 114. In some embodiments, theshutter 112 can be positioned in a first configuration such that thespring 114 is substantially compressed during normal operation of theelectrochemical cell. In some embodiments, the shutter 112 can bepositioned in a second configuration once the frangible bulb 106 breaks,wherein in the second configuration, the potential energy stored in thespring 114 is released as the spring 114 expands, causing the shutter112 to electrically disconnect the breaking contact 102 from the fixedcontact 104. In some embodiments, the CID 100 can further include a stop116 configured to define an extent of movement of the shutter 112 afterthe frangible bulb 106 breaks.

In some embodiments, when the frangible bulb 106 breaks and the shutter112 is allowed to separate the breaking contact 102 from the fixedcontact 104 by being physically interposed therebetween, the breakingcontact 102 can move while the fixed contact 102 remains substantiallyunmoved. In some embodiments, the breaking contact 102 can be moved awayfrom the fixed contact 104 by a deformation of a portion of the breakingcontact 102 without movement of the remainder of the breaking contact102 with respect to the CID 100. In some embodiments, the breakingcontact 102 can be moved away from the fixed contact 104 by moving theentire breaking contact 102 with respect to the fixed contact 104 andwithout deformation of the breaking contact 102. In some embodiments,the breaking contact 102 can be moved away from the fixed contact 104 bymoving the entire breaking contact 102 with respect to the fixed contact104 and by also deforming a portion of the breaking contact 102. In someembodiments, deformation of a portion of the breaking contact 102 can beaccomplished by allowing the shutter 112 to displace the breakingcontact 102 and for the breaking contact 102 to deform in asubstantially uncontrolled manner. In some embodiments, the breakingcontact 102 can include material or materials that are suitablydeformable at the temperature at which the frangible bulb 106 breakssuch that deformation is less likely during normal operation of theelectrochemical cell but easier under the conditions in which the CID100 is engaged. In some embodiments, the breaking contact 102 caninclude a thinned portion such that when the shutter 112 is interposedbetween the breaking contact 102 and the fixed contact 104, the breakingcontact 102 is engineered to deform by a first portion rotating aboutthe thinned portion while a second portion remains substantially intact.In some embodiments, the breaking contact 102 can be scored, etched,compressed, or otherwise manipulated to achieve the thinned portion.

In some embodiments, the CID 100 can include an enclosure 124 configuredto contain the components of the CID 100. In some embodiments, theenclosure 124 can include a first aperture by which the breaking contact102 passes from the anode tab or cathode to and into the enclosure 124,a second aperture by which the fixed contact 104 passes from inside theenclosure 124 back out to the anode tab or cathode tab, and a thirdaperture by which the frangible bulb is positioned within the enclosure124. In some embodiments, the first and second apertures can besubstantially filled by the breaking contact 102 and the fixed contact104, respectively. In some embodiments, the third aperture can be sealedclosed after the frangible bulb 106 is positioned within the enclosure124 by the placement and rotational fixture of the set screw 108 withinthe third aperture.

In some embodiments, the CID 100 can be resettable. In other words, insome embodiments, once the frangible bulb 106 breaks and the shutter 112is interposed between the breaking contact 102 and the fixed contact 104to discontinue electrical current into or out of the electrochemicalcell, portions of the CID 100 can be reset and components replaced toreturn it to the original condition. For instance, in some embodiments,the shutter 112 can be moved back into position in the firstconfiguration (re-loading the spring 114), the breaking contact 102 canbe repositioned into electrical communication with the fixed contact104, and the frangible bulb 106 can be replaced to reset the CID 100. Insome embodiments, the frangible bulb 106 can be replaced by removing theset screw 108, inserting a new frangible bulb 106 through the thirdaperture and replacing the set screw 108 to secure the frangible bulb106 in place.

In some embodiments, the CID 100 can further include a resistor 118having a designed resistance to the passage of an electric current. Insome embodiments, the resistor 118 can be a heat conductor designed toheat the frangible bulb 106 during overcurrent conditions. In someembodiments, the resistor 118 can be configured to convert current fromthe breaking contact 102 to thermal energy via resistive heating. Insome embodiments, the breaking contact 102 may be configured to directlyconvert current to thermal energy via Ohmic heating. In someembodiments, the overcurrent condition can include a C-rate duringdischarge of between about C/10 and about 200 C, between about C/10 andabout 190 C, between about C/10 and about 180 C, between about C/10 andabout 170 C, between about C/10 and about 160 C, between about C/10 andabout 150 C, between about C/10 and about 140 C, between about C/10 andabout 130 C, between about C/10 and about 120 C, between about C/10 andabout 110 C, between about C/10 and about 100 C, between about C/10 andabout 90 C, between about C/10 and about 80 C, between about C/10 andabout 70 C, between about C/10 and about 60 C, between about C/10 andabout 50 C, between about C/10 and about 40 C, between about C/10 andabout 30 C, between about C/10 and about 20 C, between about C/9 andabout 19 C, between about C/8 and about 18 C, between about C/7 andabout 17 C, between about C/6 and about 16 C, between about C/5 andabout 15 C, between about C/4 and about 14 C, between about C/3 andabout 13 C, between about C/2 and about 12 C, between about C/1 andabout 11 C, between about 1C and about 10 C, between about 2C and about9 C, between about 3C and about 8 C, between about C/10 and about 19 C,between about C/10 and about 18 C, between about C/10 and about 17 C,between about C/10 and about 16 C, between about C/10 and about 15 C,between about C/10 and about 14 C, between about C/10 and about 13 C,between about C/10 and about 12 C, between about C/10 and about 11 C,between about C/10 and about 10 C, between about C/10 and about 9 C,between about C/10 and about 8 C, between about C/10 and about 7 C,between about C/10 and about 6 C, between about C/10 and about 5 C,between about C/10 and about 4 C, between about C/10 and about 3 C,between about C/10 and about 2 C, between about C/10 and about 1 C,between about C/10 and about C/1, between about C/10 and about C/2,between about C/10 and about C/3, between about C/10 and about C/4,between about C/10 and about C/5, between about C/10 and about C/6,between about C/10 and about C/7, between about C/10 and about C/8,between about C/10 and about C/9, between about C/9 and about 200 C,between about C/8 and about 200 C, between about C/7 and about 200 C,between about C/6 and about 200 C, between about C/5 and about 200 C,between about C/4 and about 200 C, between about C/3 and about 200 C,between about C/2 and about 200 C, between about 1C and about 200 C,between about 2C and about 200 C, between about 3C and about 200 C,between about 4 C and about 200 C, between about 5 C and about 200 C,between about 6 C and about 200 C, between about 7 C and about 200 C,between about 8 C and about 200 C, between about 9 C and about 200 C,between about 10 C and about 200 C, between about 11 C and about 200 C,between about 12 C and about 200 C, between about 13 C and about 200 C,between about 14 C and about 200 C, between about 15 C and about 200 C,between about 16 C and about 200 C, between about 17 C and about 200 C,between about 18 C and about 200 C, between about 19 C and about 200 C,between about 20 C and about 200 C, between about 30 C and about 200 C,between about 40 C and about 200 C, between about 50 C and about 200 C,between about 60 C and about 200 C, between about 70 C and about 200 C,between about 80 C and about 200 C, between about 90 C and about 200 C,between about 100 C and about 200 C, between about 110 C and about 200C, between about 120 C and about 200 C, between about 130 C and about200 C, between about 140 C and about 200 C, between about 150 C andabout 200 C, between about 160 C and about 200 C, between about 170 Cand about 200 C, between about 180 C and about 200 C, or between about190 C and about 200 C, inclusive of all values and ranges therebetween.In some embodiments, the overcurrent condition can include a C-rateduring discharge of greater than about C/50, C/40, C/30, C/20, C/10,C/9, C/8, C/7, C/6, C/5, C/4, C/3, C/2, 1 C, 2 C, 3 C, 4 C, 5 C, 6 C, 7C, 8 C, 9 C, 10 C, 11 C, 12 C, 13 C, 14 C, 15 C, 16 C, 17 C, 18 C, 19 C,20 C, 30 C, 40 C, 50 C, 60 C, 70 C, 80 C, 90 C, 100 C, 110 C, 120 C, 130C, 140 C, 150 C, 160 C, 170 C, 180 C, 190 C, or 200 C, inclusive of allvalues and ranges therebetween.

In some embodiments, the resistor 118 can include a conductor (notshown) configured to heat up when the current exceeds a currentthreshold. In some embodiments, the resistor 118 can itself heat up whenthe current exceeds the current threshold. In some embodiments, theresistor 118 can include but are not limited to carbon-containingmaterials, metals, metal oxides, or other partially conductive materialsthat heat up when electrical current is caused to flow into the resistor118.

In some embodiments, the CID 100 can include a diode 120 configured toresist conduction of electrical current to a heating element 122 whenthe cell voltage is below a voltage threshold. In some embodiments, thediode 120 can be configured to conduct current from the breaking contact102 to the heating element 122 when the cell voltage reaches or exceedsthe voltage threshold. In some embodiments, the heating element 122 canconvert current coming into the diode 120 or from the diode 120 tothermal energy via resistive heating, similar to the way in which theresistor 118 operates. In some embodiments, the heating element 122 canbe positioned sufficiently close to the frangible bulb 106 such thatwhen the heating element 122 heats up to above the temperaturethreshold, the frangible bulb 106 also heats to above the temperaturethreshold and breaks. In some embodiments, the diode 120 can also act asa heat generator due to inherent resistance. In some embodiments, thediode 120 can be positioned sufficiently close to the frangible bulb 106such that when the diode 120 heats to above the temperature threshold,the frangible bulb 106 also heats to above the temperature threshold andbreaks. In some embodiments, both the diode 120 and the heating element122 can be positioned sufficiently close to the frangible bulb 106 suchthat as both the diode 120 and the heating element 122 heat up, thecombination of thermal energy produced by both the diode 120 and theheating element 122 can cause the frangible bulb 106 to heat up andbreak. In some embodiments, the heating rate of the diode 120 and/or theheating element 122 at various voltages may be tailored by adjusting theresistance of the heating element 122. In some embodiments, the heatingelement 122 can include a length of copper wire or a resistor, e.g.,similar to the resistor 118. In some embodiments, the voltage thresholdvalue can be tailored by adjusting the type and quantity of diodes 120in the CID 100. In some embodiments, the number of diodes 120 can beone, two, three, four, five, six, seven, eight, nine, ten, greater thanten, or between one and three, inclusive of all values and rangestherebetween. In some embodiments, including more than one diode 120 maylead to a reduction in the risk that at least one of the diodes 120 willinitiate heating of the frangible bulb 106 when the voltage reaches orexceeds the voltage threshold.

In some embodiments, the voltage threshold can be greater than about 1.0V, about 1.1 V, about 1.2 V, about 1.3 V, about 1.4 V, about 1.5 V,about 1.6 V, about 1.7 V, about 1.8 V, about 1.9 V, about 2.0 V, about2.1 V, about 2.2 V, about 2.3 V, about 2.4 V, about 2.5 V, about 2.6 V,about 2.7 V, about 2.8 V, about 2.9 V, about 3.0 V, about 3.1 V, about3.2 V, about 3.3 V, about 3.4 V, about 3.5 V, about 3.6 V, about 3.7 V,about 3.8 V, about 3.9 V, about 4.0 V, about 4.1 V, about 4.2 V, about4.3 V, about 4.4 V, about 4.5 V, about 4.6 V, about 4.7 V, about 4.8 V,about 4.9 V, about 5.0 V, about 5.1 V, about 5.2 V, about 5.3 V, about5.4 V, about 5.5 V, about 5.6 V, about 5.7 V, about 5.8 V, about 5.9 V,about 6.0 V, about 6.5 V, about 7.0 V, or greater than about 7.5 V,inclusive of all values and ranges therebetween. In some embodiments,the voltage threshold can be less than about 10 V, about 9.5 V, about9.0 V, about 8.5 V, about 8.0 V, about 7.5 V, about 7.0 V, about 6.5 V,about 6.0 V, about 5.5 V, about 5.0 V, about 4.9 V, about 4.8 V, about4.7 V, about 4.6 V, about 4.5 V, about 4.4 V, about 4.3 V, about 4.2 V,about 4.1 V, about 4.0 V, about 3.9 V, about 3.8 V, about 3.7 V, about3.6 V, about 3.5 V, about 3.4 V, about 3.3 V, about 3.2 V, about 3.1 V,about 3.0 V, about 2.9 V, about 2.8 V, about 2.7 V, about 2.6 V, about2.5 V, about 2.4 V, about 2.3 V, about 2.2 V, about 2.1 V, about 2.0 V,about 1.9 V, about 1.8 V, about 1.7 V, about 1.6 V, about 1.5 V, or lessthan about 1.0 V, inclusive of all values and ranges therebetween. Insome embodiments, the voltage threshold can be between about 1.0 V andabout 10 V, between about 1.5 V and about 9.5 V, about 2.0 V and about9.0 V, between about 2.5 V and about 8.5 V, between about 3.0 V andabout 8.0 V, between about 3.5 V and about 7.5 V, between about 4.0 Vand about 7.0 V, between about 4.5 V and about 6.5 V, between about 5 Vand about 6 V, or between about 4 V and about 6.0 V, inclusive of allvalues and ranges therebetween.

In some embodiments, the CID 100 can be positioned sufficiently close tothe electrochemical cell to which it is electrically coupled. In someembodiments, the CID 100 can be positioned suitably close to theelectrochemical cell such that a temperature of the frangible bulb 106is substantially similar to an operating temperature of theelectrochemical cell. In other words, the CID 100 can be positionedsufficiently close to the electrochemical cell such that the frangiblebulb 106 breaks when the temperature within the electrochemical cell issubstantially similar to the temperature threshold of the frangible bulb106. In some embodiments, the frangible bulb is place sufficiently closeto a cell terminal that the frangible bulb 106 breaks when thetemperature of the terminal is substantially similar to the temperaturethreshold of the frangible bulb 106. In some embodiments, this terminalis internal to the cell. In some embodiments, this terminal is externalto the cell. In some embodiments, the temperature threshold can be atemperature range. In some embodiments, the enclosure 124 can include apass-through (not shown) whereby thermal energy from the electrochemicalcell can more readily equalize the temperature between theelectrochemical cell and the CID 100. In some embodiments, a thermallyconductive element can pass through the enclosure 124 and be configuredto thermally couple the CID 100 to the electrochemical cell such thatthe CID 100 can experience substantially the same temperature changesexperienced by the electrochemical cell. In some embodiments, forexample in applications with high ambient temperatures outside of theelectrochemical cell and/or CID 100, the enclosure 124 can be thermallyinsulated on most or many sides and thermally conductive on at least oneside adjacent to the electrochemical cell. In this way, the enclosure124 may make the CID 100 relatively immune to temperature fluctuationsnot related to the electrochemical cell while being responsive totemperature fluctuations that are related to the electrochemical cell.

In some embodiments, the CID 100 can prevent unwanted and/oruncontrolled short circuit of the electrochemical cell. In someembodiments, at high currents (e.g. during short circuit events), thebreaking contact 102 may begin to self-heat via ohmic heating. As it isin close proximity with the frangible bulb 106, the frangible bulb 106is also heated. When the threshold temperature is reached, the frangiblebulb 106 activates and shatters. The shutter 112 then activates,separating the breaking contact 102 from the fixed contact 104 andinterrupting further current flow coming from or going into theelectrochemical cell.

In some embodiments, the resistor 118 can be positioned and configuredto hold the frangible bulb 106 in place during normal operation of theelectrochemical cell, e.g., before the frangible bulb 106 breaks. Insome embodiments, the resistor 118 can create or partially create achannel occupied by the frangible bulb 106 and which disallows unwantedmovement of the frangible bulb 106, which could lead to unintendeddisconnection of the breaking contact 102 from the fixed contact 104. Insome embodiments, the heating element 122 or the breaking contact 102can also or alternatively create or partially create the channeloccupied by the frangible bulb 106 and which disallows unwanted movementof the frangible bulb 106.

In some embodiments, during assembly of the CID 100, the shutter 112 canbe positioned out of the way of the breaking contact 102 and fixedcontact 104. In some embodiments, the shutter 112 can include atensioning ribbon (not shown) connected to a non-tapered portion of theshutter 112, the tensioning ribbon extending through the enclosure 124.In some embodiments, the tensioning ribbon can be retracted further fromthe enclosure 124 to apply compressive force against the spring 114 andto position the shutter 112 appropriately to accommodate the frangiblebulb 106. In some embodiments, the frangible bulb 106 can then beinserted through a cavity in the enclosure 124 and into the channelformed by at least one of the resistor 118 and the heating element 122and the set screw 108 can be wound into place in the cavity to hold thefrangible bulb 106 in place. In some embodiments, the tensioning ribboncan then be released to allow the shutter 112 to be properly positionedsuch that when the frangible bulb 106 breaks, the tensioned spring 114can cause the shutter 112 to electrically disconnect the breakingcontact 102 from the fixed contact 104.

While CID 100 is shown in FIGS. 1, 2, 3A, and 3B as including theresistor 118, the diode 120, the heating element 122, the set screw 108,and the contact pad 116, the CID 100 could also be formed and used thatdoes not use at least one of these elements. In some embodiments, theCID 100 could include the breaking contact 102 and the fixed contact 104held in electrical contact by the frangible bulb 106. In someembodiments, the frangible bulb 106 can be configured to break at thetemperature threshold and release a shutter 112. In some embodiments,the shutter can be configured to be interposed by the release of acoiled spring, e.g., spring 114, between the breaking contact 102 andthe fixed contact 104. In some embodiments, the interposed shutter 112can stop or substantially stop the charging or discharging of theelectrochemical cell to which the CID 100 is operably coupled. In someembodiments, the CID 100 can be positioned sufficiently nearby theelectrochemical cell such that the temperature of the liquid within thefrangible bulb 106 is substantially similar to the operating temperatureof the electrochemical cell. In that way, in the event that theelectrochemical cell experiences thermal runaway or anotherover-temperature condition, the frangible bulb 106 can break, initiatingthe CID 100 to disconnect electrical current between the breakingcontact 102 and the fixed contact 104. In some embodiments, the CID 100can include one of the resistor 118 and the diode 120 plus the heatingelement 122. In some embodiments, the CID 100 can include the resistor118 such that the CID 100 is capable of protecting againstover-temperature conditions and over-current conditions. In someembodiments, the CID 100 can include the diode 120 and the heatingelement 122 such that the CID 100 is capable of protecting againstover-temperature conditions and over-voltage conditions.

In some embodiments, more than one CID, e.g., CID 100, can be operablycoupled to the electrochemical cell. In some embodiments, a first CIDcan be electrically coupled to the anode tab and a second CID can beelectrically coupled to the cathode tab. In this way, theelectrochemical cell can be protected from faulty battery operation andfailure conditions during both charging and discharging with someredundancy due to the presence of the second CID. In some embodiments,more than one CID can be operably coupled to one of the anode tab andthe cathode tab. In some embodiments, one of the CIDs can beelectrically coupled nearby the electrochemical cell and can beconfigured to disconnect electrical current due to a high and precisetemperature threshold while not being configured to disconnectelectrical current due to the current threshold or the voltagethreshold. In some embodiments, one CID can be operably coupled furtherfrom the electrochemical cell and can be configured to disconnectelectrical current in response to one or both of a current threshold andthe voltage threshold. In other words, in some embodiments, a first CIDcan include a frangible bulb (e.g., frangible bulb 106) configured tobreak at a precise temperature and can be sufficiently close to theelectrochemical cell such as to minimize the delay between when theelectrochemical cell reaches the temperature threshold and when thefrangible bulb breaks. In addition, in some embodiments, the other CIDcan be positioned further away from the electrochemical cell and caninclude a frangible bulb configured to break at a lower temperaturethreshold than the frangible bulb of the closer positioned CID. In someembodiments, the further positioned CID can be more immune to thefluctuations in operating temperature of the electrochemical cell whilerequiring a more slight change in temperature due to over-current orover-voltage conditions to break the frangible bulb in the second CID.

In some embodiments, the CID 100 can operate by disconnecting electricalconnection between the breaking contact 102 and the fixed contact 104due to at least one of over-temperature conditions, overcurrentconditions, overvoltage conditions, short-circuit conditions,overcharging, physical damage to the CID 100, or thermal runaway of theelectrochemical cell. In some embodiments, the CID 100 can be activatedwhen only one of these conditions exist. For instance, in someembodiments, the CID 100 might be activated if the electrochemical cellis simply overcharged but is otherwise operating properly duringdischarge. In some embodiments, the CID 100 might be activated if theelectrochemical cell experiences a build-up of gas due to theelectrochemical reactions occurring in the cell and if the gas causesdamage to the CID 100 during a gas-related cell failure event. In someembodiments, heat from the anode reaction may increase the operatingtemperature of the electrochemical cell, which may cause the breakdownof the organic solvents used as the electrolyte, releasing flammablehydrocarbon gases and building up pressure in the cell. In someembodiments, the flammable hydrocarbon gases can ignite, causing a smallfire and damaging the cell but not causing catastrophic failure. In someembodiments, the CID 100 can be activated in such instances todiscontinue charging or discharging of the electrochemical cell so thatfurther anode reaction does not occur, discontinuing further gasbuild-up in the cell. In each of these and many other battery failureconditions, the CID 100 described herein can be activated and currentsafely disconnected across the cathode tab and/or the anode tab.

FIGS. 4 and 5 show an electrochemical cell 20 including a currentinterrupt device 200 (CID 200) positioned and configured to create asoft short circuit or a hard short circuit during at least one of anover-current condition, an over-voltage condition, and anover-temperature condition within the electrochemical cell 20. In someembodiments, a high short magnitude may be helpful in order to shunt theovercharge current during failure of the electrochemical cell 20. Insome embodiments, the CID 200 can be operably and/or electricallycoupled to one of a cathode tab or an anode tab. The CID 200 includes ashorting contact 202 and a fixed contact 204, the shorting contact 202configured to remain electrically disconnected from the charging ordischarging current during normal operation of the electrochemical cell20. In some embodiments, as shown in FIG. 5, the shorting contact 202can be positioned such that a spring 214 is loaded and a frangible bulb206 is positioned such that the spring 214 remains loaded. The frangiblebulb 206 can be substantially similar to the frangible bulb 106described above and is therefore not described in further detail here.In some embodiments, the frangible bulb 206 can include a liquid and/ora gas that expands due to increased temperatures such that the frangiblebulb 206 is configured to break at or above a particular temperaturethreshold.

In some embodiments, the shorting contact 202 can be coupled to a movingend of the spring 214 and a fixed end of the spring 214 can be coupledto an enclosure 224. In some embodiments, the fixed contact 204, thespring 216, and the shorting contact 202 can each be electricallyconducting. In some embodiments, when the frangible bulb 206 breaks, thespring 214 is unloaded, the moving end of the spring 214 moves theshorting contact 202 into electrical connection with a conductivematerial, and the charging or discharging current is diverted throughthe soft short circuit or hard short circuit.

In some embodiments, the CID 200 can include a contact pad 216, thecontact pad 216 including an electrically insulating material andpositioned between the frangible bulb 206 and the distal end of thefixed contact 204. In some embodiments, the contact pad 216 may protectthe frangible bulb 206 from electrical current-related and/or vibratoryfailure.

In some embodiments, when the frangible bulb 206 breaks, the shortingcontact 202 can be forced into electrical contact with the batteryenclosure, casing, a terminal, an extension pad connected to a terminal,or any other suitable material such that the current through the cathodetab or the anode tab is diverted through the soft short circuit or hardshort circuit.

In some embodiments, the CID 200 can be configured to interrupt currentto or from the electrochemical cell 20 by creating a soft short circuitor a hard short circuit that can be reversed to return theelectrochemical cell 20 to normal operation. In other words, after theCID 200 is activated and electrochemical activity within theelectrochemical cell 20 is terminated to protect against catastrophicfailure events, the CID 200 can be reset and the electrochemical cell 20can be returned to normal operation. In some embodiments, the CID 200can be reset by reloading the spring 214 and positioning a replacementfrangible bulb 206 into place within the CID 200. In some embodiments,as soon as the shorting contact 202 is moved back into place, thecurrent can return to being communicated through the anode tab or thecathode tab.

In some embodiments, the CID 200 can operate by causing a soft shortcircuit or a hard short circuit to occur due to at least one ofover-temperature conditions, overcurrent conditions, overvoltageconditions, short-circuit conditions, overcharging, physical damage tothe CID 200, or thermal runaway of the electrochemical cell 20. In someembodiments, the CID 200 can be activated when only one of theseconditions exist. For instance, in some embodiments, the CID 200 mightbe activated if the electrochemical cell is simply overcharged but isotherwise operating properly during discharge. In some embodiments, theCID 200 might be activated if the electrochemical cell experiences abuild-up of gas due to the electrochemical reactions occurring in thecell and if the gas causes damage to the CID 200 during a gas-relatedcell failure event. In some embodiments, the CID 200 might be activatedif a solvent electrolyte from one electrode of the electrochemical cellleaks across a separator to the other electrode and causes theelectrochemical cell to discharge the other electrode or currentcollector thereof. In some embodiments, heat from the anode reaction mayincrease the operating temperature of the electrochemical cell, whichmay cause the breakdown of the organic solvents used as the electrolyte,releasing flammable hydrocarbon gases and building up pressure in thecell. In some embodiments, the flammable hydrocarbon gases can ignite,causing a small fire and damaging the cell but not causing catastrophicfailure. In some embodiments, the CID 200 can be activated in suchinstances to discontinue charging or discharging of the electrochemicalcell so that further anode reaction does not occur, discontinuingfurther gas build-up in the cell. In each of these and many otherbattery failure conditions, the CID 200 described herein can beactivated and current safely disconnected across the cathode tab and/orthe anode tab. Without wishing to be bound by any particular theory, theformation of a soft to hard short circuit due to the activation of theCID 200 may allow the electrochemical cell 20 to be discharged in a morecontrolled manner, putting the electrochemical cell 20 into a safer,lower-energy state.

In some embodiments, the heating of the frangible bulb 206 can becontrolled by engineering a precise resistance to current at some pointin the CID 200. In some embodiments, current resistance can becontrolled by contact geometry, material, and/or an in-line resistor. Insome embodiments, the CID 200 can include a diode (e.g., diode 120), aheating element (e.g., heating element 122), and/or a resistor (e.g.,118).

FIGS. 6-8 show an electrochemical cell 30 including a cathode tab 32, ananode tab 34, and a current interrupt device 300 (CID 300), the CID 300configured to protect the electrochemical cell 30 from least one of anover-current condition, an over-voltage condition, and anover-temperature condition within the electrochemical cell 30. In someembodiments, the electrochemical cell 30 can have any suitable formfactor, including but not limited to, a pouch cell, a can, a stackedpouch cell, etc. In some embodiments, the CID 300 can be configured topuncture an enclosure material of the electrochemical cell 30 due tothermal activation of the CID 300 to prevent failure of theelectrochemical cell 30. In some embodiments, the CID 300 can bepositioned nearby one or both of the cathode tab and the anode tab.

In some embodiments, the CID 300 can include, as shown in FIG. 8, aspring 314 at least partially in tension during normal operation of theelectrochemical cell 30. In some embodiments, the spring can have anysuitable form factor, including but not limited to a spring, a leafspring, a torsion spring, axial spring, etc. The CID 300 also includes ashutter 312 configured to puncture the enclosure material of theelectrochemical cell when the CID 300 is activated. In some embodiments,the shutter 312 can include a shutter base 312A, a shutter arm 312Bcoupled to the shutter base 312A and extending a distance from theshutter base 312A, and a shutter blade 312C coupled to the shutter arm312B. In some embodiments, the spring 314 can be configured to becoupled to, positioned interlinkingly about, or can comprise the shutterbase 312A. In some embodiments, the shutter base 312A can be dimensionedand configured to receive force supplied by the spring 314 uponactivation of the CID 300. In some embodiments, the force supplied bythe spring 314 can include but is not limited to rotational force,restoring force caused by a loaded spring returning to its lowest energystate, or another suitable force. When force is supplied by the spring314 to the shutter 312, the shutter base 312A rotates about an axis,rotating the shutter arm 312B, and moving the shutter blade 312C,causing the shutter blade 312C to puncture the enclosure material of theelectrochemical cell. In some embodiments, when the enclosure materialof the electrochemical cell 30 is punctured, the gas or gases formedduring the over-current, over-voltage, and/or over-temperature conditionwithin the electrochemical cell 30 are allowed to escape, reducing therisk of catastrophic failure of the electrochemical cell 30.

As shown in FIG. 8, the CID 300 includes a frangible bulb 306 configuredto break at a temperature threshold. The frangible bulb 306 can besubstantially similar to the frangible bulb 106 described above and istherefore not described in further detail here. In some embodiments, thefrangible bulb 306 can include a liquid and/or a gas that expands due toincreased temperatures such that the frangible bulb 306 is configured tobreak at or above a particular temperature threshold. In someembodiments, the frangible bulb 206 can be positioned within anenclosure 324 of the CID 300 such that rotational motion of the shutter312 is substantially disallowed. In some embodiments, the shutter 312can include a contact surface 312D, as shown in FIG. 8, against whichthe frangible bulb 306 can be positioned such that the shutter 312 isunable to rotate due to the force supplied by the spring 314. In otherwords, in some embodiments, the position of the frangible bulb 306ensures that the shutter blade 312C is unable to puncture the enclosurematerial of the electrochemical cell 30 before the frangible bulb 306breaks.

In some embodiments, the shutter base 312A, shutter arm 312B, shutterblade 312C, and/or shutter contact surface 312D can include or be formedfrom the same material. In some embodiments, the shutter blade 312C caninclude a material that is sufficiently durable such that when theshutter blade 312C is rotatably moved into contact with the enclosurematerial of the electrochemical cell 30, the shutter blade 312C is ableto puncture the enclosure material. In some embodiments, the shutterblade 312C is configured to include a sharp point, sharp edge, and/or aneedle. In some embodiments, the shutter blade 312C can include a metalmaterial, a polymer material, a plastic material, a mineral material, aceramic material, or combinations thereof.

In some embodiments, the frangible bulb 306 can be positioned in the CID300 by inserting the frangible bulb 306 through an aperture (not shown)in the CID 300 and can be removably sealed into place by inserting a setscrew 308 into the aperture. In some embodiments, the frangible bulb 306can be positioned within the CID 300 before the CID 300 is coupled tothe electrochemical cell 30. In some embodiments, the CID 300 can becoupled to the electrochemical cell 30 and the frangible bulb 306 cansubsequently be positioned within the CID 300. In some embodiments, theCID 300 can include a tensioning ribbon (not shown) connected to one ofthe shutter base 312A, shutter arm 312B, or the shutter contact surface312D and extending through the enclosure 324 of the CID 300. In someembodiments, when setting the CID 300, the shutter 312 and the spring314 can be positioned to accommodate the frangible bulb 306 by pullingon the tensioning ribbon, inserting the frangible bulb 306 through theaperture in the CID 300, and inserting the set screw 308 into theaperture to seal the frangible bulb 306 in place.

In some embodiments, current resistance can be controlled by contactgeometry, material, and/or an in-line resistor. In some embodiments, theCID 300 can include a diode (e.g., diode 120), a heating element (e.g.,heating element 122), and/or a resistor (e.g., 118).

In some embodiments, the CID 300 can operate by causing the release ofgas built up in the electrochemical cell 30 due to at least one ofover-temperature conditions, overcurrent conditions, overvoltageconditions, short-circuit conditions, overcharging, physical damage tothe CID 300, or thermal runaway of the electrochemical cell. In someembodiments, the CID 300 can be activated when only one of theseconditions exist. For instance, in some embodiments, the CID 300 mightbe activated if the electrochemical cell is simply overcharged but isotherwise operating properly during discharge. In some embodiments, theCID 300 might be activated if the electrochemical cell experiences abuild-up of gas due to the electrochemical reactions occurring in thecell and if the gas causes damage to the CID 300 during a gas-relatedcell failure event. In some embodiments, the CID 300 might be activatedif a solvent electrolyte from one electrode of the electrochemical cellleaks across a separator to the other electrode and causes theelectrochemical cell to discharge the other electrode or currentcollector thereof. In some embodiments, heat from the anode reaction mayincrease the operating temperature of the electrochemical cell, whichmay cause the breakdown of the organic solvents used as the electrolyte,releasing flammable hydrocarbon gases and building up pressure in thecell. In some embodiments, the flammable hydrocarbon gases can ignite,causing a small fire and damaging the cell but not causing catastrophicfailure. In some embodiments, the CID 300 can be activated in suchinstances to discontinue charging or discharging of the electrochemicalcell so that further anode reaction does not occur, discontinuingfurther gas build-up in the cell. In each of these and many otherbattery failure conditions, the CID 300 described herein can beactivated and current safely disconnected across the cathode tab and/orthe anode tab.

FIGS. 9 and 10 show an electrochemical cell 40 having a cathode tab 42,an anode tab 44, and a current interrupt device 400 (CID 400), the CID400 configured to protect the electrochemical cell 40 from least one ofan over-current condition, an over-voltage condition, and anover-temperature condition within the electrochemical cell 40. In someembodiments, the CID 400 can be positioned nearby one of the cathode tab42 and the anode tab 44 such that when the CID 400 is activated,electrical current through at least one of the cathode tab 42 and theanode tab 44 is discontinued. In some embodiments, the CID 400 can beelectrically integrated into the cathode tab 42 or the anode tab 44. Insome embodiments, one of the cathode tab 42 and the anode tab 44 caninclude two portions interposed by the CID 400 such that all electricalcurrent passing through the cathode tab 42 or the anode tab 44 alsopasses through the CID 400.

In some embodiments, the CID 400 can include a breaking contact 402 anda fixed contact 404 positioned and configured to be in electricalcontact during normal operation of the electrochemical cell 40. In someembodiments, the CID 400 can include a frangible bulb 406 configured tohold the breaking contact 402 in electrical contact with the fixedcontact 404 due to the dimensions and position of the frangible bulb 406within the CID 400. The frangible bulb 406 can be substantially similarto the frangible bulb 106 described above and is therefore not describedin further detail here. In some embodiments, the frangible bulb 406 caninclude a liquid and/or a gas that expands due to increased temperaturessuch that the frangible bulb 406 is configured to break at or above aparticular temperature threshold.

In some embodiments, the CID 400 can include a contact pad 416positioned between the breaking contact 402 and the frangible bulb 406such that the frangible bulb 406 is less susceptible to current-relatedor vibratory failure when the electrochemical cell 40 is operatingnormally. In some embodiments, the CID 400 can include an enclosure 424having an orifice (not shown) through which the frangible bulb 406 canbe inserted into the CID 400. In some embodiments, the CID 400 caninclude a set screw 408 that is inserted into the orifice and that isconfigured to keep the frangible bulb 406 in place within the CID 400.In some embodiments, current resistance can be controlled by contactgeometry, material, and/or an in-line resistor. In some embodiments, theCID 400 can include a diode (e.g., diode 120), a heating element (e.g.,heating element 122), and/or a resistor (e.g., 118).

In some embodiments, the CID 400 can include a shutter 412 having adistal end configured to be interposed between the breaking contact 402and the fixed contact 404 when the CID 400 is activated. In someembodiments, the CID 400 can include a spring 414 operably coupled tothe shutter 412 and configured to supply sufficient force to the shutter412 to interpose the shutter 412 between the breaking contact 402 andthe fixed contact 404 when the CID 400 is activated. In someembodiments, the distal end of the shutter 412 can taper and/or caninclude a blade such that the force supplied by the movement of theshutter 412 upon activation of the CID 400 is sufficient to interposethe shutter 412 between the breaking contact 402 and the fixed contact404. In some embodiments, interposing the shutter 412 between thebreaking contact 402 and the fixed contact 404 can include deformationor movement of the breaking contact 402. In some embodiments, when thetemperature of the gas and/or the liquid within the frangible bulb 406equals or exceeds the temperature threshold, the frangible bulb 406breaks, allowing the force of the preloaded spring 414 to cause theshutter 412 to be interposed between the breaking contact 402 and thefixed contact 404.

In some embodiments, the frangible bulb 406 can be positioned in the CID400 by inserting the frangible bulb 406 through an aperture (not shown)in the CID 400 and can be removably sealed into place by inserting a setscrew 408 into the aperture. In some embodiments, the frangible bulb 406can be positioned within the CID 400 before the CID 400 is coupled tothe electrochemical cell 40. In some embodiments, the CID 400 can becoupled to the electrochemical cell 40 and the frangible bulb 406 cansubsequently be positioned within the CID 400. In some embodiments, theCID 400 can include a tensioning ribbon (not shown) connected to one ofthe shutter 412 and the spring 414, and extending through the enclosure424 of the CID 400. In some embodiments, when setting the CID 400, theshutter 412 and the spring 414 can be positioned to accommodate thefrangible bulb 406 by pulling on the tensioning ribbon, positioning thebreaking contact 402 in electrical contact with the fixed contact 404,inserting the frangible bulb 406 through the aperture in the CID 400,and inserting the set screw 408 into the aperture to seal the frangiblebulb 406 in place.

In some embodiments, since the CID 400 can be integrated into thecathode tab 42 or the anode tab 44, if the frangible bulb 406 breaks forwhatever reason during normal operation of the electrochemical cell 40,the electrochemical cell 40 will discontinue operation. It can behelpful then, in some embodiments, to include more than one frangiblebulb 406 such that if some but not all of the frangible bulbs 406 break,the CID 400 will continue to allow current through the cathode tab 42 orthe anode tab 44 and normal operation of the electrochemical cell 40will continue.

In some embodiments, the CID 400 can operate by disconnecting electricalconnection between the breaking contact 402 and the fixed contact 404due to at least one of over-temperature conditions, overcurrentconditions, overvoltage conditions, short-circuit conditions,overcharging, physical damage to the CID 400, or thermal runaway of theelectrochemical cell. In some embodiments, the CID 400 can be activatedwhen only one of these conditions exist. For instance, in someembodiments, the CID 400 might be activated if the electrochemical cellis simply overcharged but is otherwise operating properly duringdischarge. In some embodiments, the CID 400 might be activated if theelectrochemical cell experiences a build-up of gas due to theelectrochemical reactions occurring in the cell and if the gas causesdamage to the CID 400 during a gas-related cell failure event. In someembodiments, the CID 400 might be activated if a solvent electrolytefrom one electrode of the electrochemical cell leaks across a separatorto the other electrode and causes the electrochemical cell to dischargethe other electrode or current collector thereof. In some embodiments,heat from the anode reaction may increase the operating temperature ofthe electrochemical cell, which may cause the breakdown of the organicsolvents used as the electrolyte, releasing flammable hydrocarbon gasesand building up pressure in the cell. In some embodiments, the flammablehydrocarbon gases can ignite, causing a small fire and damaging the cellbut not causing catastrophic failure. In some embodiments, the CID 400can be activated in such instances to discontinue charging ordischarging of the electrochemical cell so that further anode reactiondoes not occur, discontinuing further gas build-up in the cell. In eachof these and many other battery failure conditions, the CID 400described herein can be activated and current safely disconnected acrossthe cathode tab and/or the anode tab.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Where schematics and/or embodiments described above indicatecertain components arranged in certain orientations or positions, thearrangement of components may be modified. While the embodiments havebeen particularly shown and described, it will be understood thatvarious changes in form and details may be made. Although variousembodiments have been described as having particular features and/orcombinations of components, other embodiments are possible having acombination of any features and/or components from any of embodimentsdescribed herein.

The specific configurations of the various components can also bevaried. For example, the size and specific shape of the variouscomponents can be different from the embodiments shown, while stillproviding the functions as described herein. More specifically, the sizeand shape of the various components can be specifically selected for adesired or intended usage. Thus, it should be understood that the size,shape, and/or arrangement of the embodiments and/or components thereofcan be adapted for a given use unless the context explicitly statesotherwise.

Where methods and/or events described above indicate certain eventsand/or procedures occurring in certain order, the ordering of certainevents and/or procedures may be modified. Additionally, certain eventsand/or procedures may be performed concurrently in a parallel processwhen possible, as well as performed sequentially as described above.

1. A current interrupt device, comprising: a frangible bulb; a fixedcontact; and a breaking contact configured to be held in electricalcontact with the fixed contact by the frangible bulb in a firstconfiguration, and to be electrically disconnected from the fixedcontact in a second configuration after the frangible bulb breaks. 2-20.(canceled)